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The adsorption properties of magnesium oxide in two different physical types - large micron-sized crystals (CM-MgO) and nanoscale crystals (AP-MgO) are reported. The enhanced reactivities of the nanoscale MgO, halogen adducts as halogenating agents of organic molecules and their noticeable biocidal activity are explained.

The pore structure and adsorption properties of nanocrystaline pellets of magnesium oxide are examined, focusing on nanocrystaline powders and nanocrystalline pellets. A hydraulic press is used to compress the nanocrystalline powders, while a Stokes Tablet machine is employed to produce pellets with various compressions from powdered materials. The results are tabulated and graphed.

The HRTEM study indicates that the composition of the mineral constituent in the carbon-mineral materials was not changed by the carbon deposition. A singular balanced Lorentzian line owing to carbon deposits has been observed in the ESR range of the carbon-mineral materials.

A unique polymerization reaction involving alkylsilanes and water catalyzed by gold nanoparticle surfaces is reported. A simple reflux reaction is used to prepare a large quantity of siloxane, nanowires, filaments, and tubes.

The effects of the molar ratio of sodium sulfide to chloroauric acid in the range of 0.5 to 5 and the time factor on the formation of the nanoparticles (NPs) of metallic Au, Au2S or their mixtures have been studied applying in situand ex situtechniques (UV-Vis absorption spectroscopy, potentiometry, TEM, SPM, SERS, XPS). The products and intermediates have been compared with those for the reduction of chloroaurate with citrate ions and combinations of citrate and sulfide ions. An increase in the concentration of sulfide ions accelerates the reduction of Au(iii) complexes but hinders the nucleation and growth of Au NPs, resulting in a prolonged period before the appearance of plasmon peaks. The electrochemical potential is not directly associated with the plasmon intensities, although the potential sharply decreases simultaneously with a blue shift of the near-IR peak emerging with the Na2S/HAuCl4ratios of 0.5 to 1.5. It was concluded that the peak is due to longitudinal plasmon resonance of gold nanoplates. Au2S NPs, the nucleation of which is effectively inhibited, and probably some structures and fragments visible in TEM and AFM, including 2–5 nm Au NPs, crystallize in part outside the solutions. The evidence of partially liquid mesoscale structures comprising intermediate gold species as precursors of nanoparticles is presented, and their origin, ex situtransformation and role in the reaction mechanisms are discussed. [ABSTRACT FROM AUTHOR]